Car will not roll backwards in neutral- help?

[11secDSM]

I just got my trans back today and noticed the car will not roll backwards, in neutral, with the car not running. While the trans was out awaiting a new converter, I pulled the trans pump to have it checked (everything checked out), and I also pulled the valve body to make sure the pressure adjustments were turned all the way up.

I went ahead and pulled the trans pan to check if the selector was lined up with the valve body and it was. I also pulled the valve body off and it still will not allow the wheels to roll backwards.

Before I go and pull the trans back off, would something in the pump or front clutch basket prevent the car from rolling backwards?

 

[Boostdriven]

This might be a stupid idea but its an idea to check before you take the tranny out. Is it possible that your e-brake is not releasing all the way and not allowing the car to roll backwards. You can have the e-brake all the way down but it could still grab just enough to hold the car in neutral. If you put the car in reverse does it roll backwards with ease or you have to give it a little bit of throttle for it to actually go backwards? When the engine is off you should be able to roll the car forward and backwards in any gear on a automatic tranny.

 

[11secDSM]

I wish it was that simple. Not sure if I stated it, but the car rolls forward with almost no effort so something is mechanically binding in the trans. I have not started the car yet and wont until i sort this out.

 

[Boostdriven]

Does the car roll backwards in reverse or in drive?

 

[11secDSM]

Nope.

 

[Boostdriven]

Interesting, I don't know enough about the auto trannys but as far as I know an auto tranny is not engaged in any gears until the engine is running and the pump is pumping oil. So if the car is rolling forward when its not in park I would think it should roll backwards as well. Pick up the rear end so both tires are in the air and try to rotate one tire backwards. Reason I say this because I've seen where a car sat for a while and after it would roll forward but not backwards and it was due to the e-brake. Most of the time when the e-brake is used is when the car is rolling forward so it will wear out the pads a certain way causing them to slip rolling forward but grab when rolling backwards. Might be worth a try.

 

[11secDSM]

Not brake related. I have the tcase off. Its definitely a trans issue.

 

[Boostdriven]

It doesn't matter if you have the tcase on or off if the tires are on the ground that's the first thing that has to spin before anything else does. This is just an idea to check.

 

[11secDSM]

Tcase off and front tires in the air. Ebrake doesnt affect anything. Front and rear are no longer connected.

 

[Boostdriven]

Well how do you roll the car backwards if the front tires are in the air on the jack stands or whatever? You need to be more specific about how you do the tests, you said car won't roll backwards so its safe to assume that all 4 wheels are on the ground so then it don't matter if you have the tcase on or not.

 

[11secDSM]

...I appreciate you trying to help, but let's move on from the brakes. I know how to diag issues, just not 100% sure of the cause in this case.


Yes, the car will not roll backwards w/ 4 wheels on the ground...that's how I found out originally. The car is currently jacked up in the front w/ the tcase removed. That is how I narrowed the issue down to the trans. Fronts don't roll backwards. With the fronts on wheel dollies, the rear wheels roll fine. I am 100% sure it's trans related. I'm 75% sure I know what the issue is but i'd like someone to confirm (w/o me biasing the answer) before I pull the trans again.

 

[Boostdriven]

Well if you would of said all that in your first post we could have saved some hard drive space on tuners I've never tore an auto apart so I can't even guess what could be causing that problem, I'm sure there are some auto wizards on here that might be able to help you out. Sorry I tried

 

[5150DSM]

Pump should have no effect. All clutches, brakes and bands are released or ineffective while in neutral... according to the ATSG guide I have anyway. Sounds like the front or center dif may be binding to me.

 

[DSMnoobsause]

is the shifter out of adjustment causing it to still be in gear?

 

[11secDSM]

No. Shifter is now disconnected. Neutral hole on selector is lined up.

Just to update...I've spoken to a few people who have a clue about these transmissions and from the sounds of it either the pump or stack has an alignment issue from being installed on it's side. I'll update again once I dig in...hopefully by Monday.

 

[Raymond1927]

What was the problem?? as I am having this same issue.

 

[11secDSM]

Something was not lined up in the front clutch stack. When I pulled the trans again, I pulled the pump and stack out and reinstalled with the trans standing on its side, everything was ok after that.

 

[Maxthepersonz]

Something was not lined up in the front clutch stack. When I pulled the trans again, I pulled the pump and stack out and reinstalled with the trans standing on its side, everything was ok after that.

I'm sending you a PM

 

[Lou98GSX]

After you had the trans back together did you try to spin the input shaft by hand .